// Copyright 2017 JanusGraph Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.janusgraph.util.stats;
import com.google.common.base.Preconditions;
/**
* @author Matthias Broecheler (me@matthiasb.com)
*/
public class NumberUtil {
public static boolean isPowerOf2(long value) {
return value>0 && Long.highestOneBit(value)==value;
}
/**
* Returns an integer X such that 2^X=value. Throws an exception
* if value is not a power of 2.
*
* @param value
* @return
*/
public static int getPowerOf2(long value) {
Preconditions.checkArgument(isPowerOf2(value));
return Long.SIZE-(Long.numberOfLeadingZeros(value)+1);
}
}